Bread wheat (Triticum aestivum L.) provides approximately 20% of the calories consumed by humankind. The increasing world demand for cereals requires improved strategies to reduce yield losses due to pathogens. Wheat stripe rust, caused by the fungus Puccinia striiformis f. sp. tritici (PST, Table 1) affects millions of hectares of wheat and virulent races that appeared within the last decade are causing large yield losses (Singh et al., 2004). Historically, resistant varieties have provided an economical and “environmentally friendly” method to control stripe rust. Numerous race-specific resistance genes have been deployed by breeders, but each had limited durability presumably because of rapid pathogen evolution. In contrast, broad-race resistance genes (i.e. “slow-rusting”) have a broader spectrum of resistance and are generally more effective at adult plant stages, provide partial resistance, and usually confer more durable resistance than race-specific genes (Singh et al., 2004). Unfortunately, our understanding of broad-race resistance is limited because none of these genes has yet been cloned.